Beverage dispensers are used throughout the world in public facilities such as cafeterias, bars, restaurants, arenas and stadiums to dispense carbonated beverages, water, and other beverages to consumers. These dispensers usually employ either mechanical refrigeration systems or bulk refrigerants, such as ice, to cool the beverages before dispensing.
In many locations where the beverages are sold, such as ball parks, picnics, and carnivals, it is either impossible or impractical to use a large mechanical refrigeration system, and in these instances, bulk refrigeration is desirable because the bulk refrigerant, e.g. ice, is potable so that it can be included in the drink after the beverage is dispensed into the cup.
When beverages are cooled by bulk refrigeration, an ice bin is typically provided with a "cold plate" which forms the bottom of the ice bin. The ice is placed within the bin on the top of the cold plate so that the ice is accessible to the user to include in the drink. The cold plate is generally constructed of an aluminum casting having stainless steel tubing imbedded therein in serpentine shaped fluid passages within which the beverages and/or beverage components (syrups and water) are passed before they are dispensed. The ice on top of the cold plate thus cools the beverages and/or beverage components traveling through the serpentine passages via the heat conducted through the aluminum cold plate. Commonly, two beverage components, such as carbonated water and syrup, are mixed at the dispensing valve. With this arrangement, the consumer is provided with a chilled beverage and a source for ice to include in the beverage. A beverage dispensing apparatus of this general type is further disclosed in U.S. Pat. No. 4,555,045, the disclosure of which is incorporated by reference.
Although bulk refrigeration is a common method of cooling carbonated beverages, this method does have several drawbacks. For example, the heat transfer from the beverage to the ice is limited because of the ice surface area in contact with the cold plate surface. This is due to the physical design limitations of the ice bin, and air pockets between the ice cubes, which prevent the cubes from completely covering the cold plate surface.
Another drawback of bulk refrigeration is that the volume of beverages that can be cooled by this refrigeration method necessarily depends on the physical size of the cold plate. Because the beverages and/or beverage components must travel through the cold plate prior to dispensing, the number of lines that can pass through the plate is a function of the width, height and thickness of the plate. Thus, the number of fountain dispenser valves and the number of customers served is limited by the size of the cold plate. In many business establishments which dispense large quantities of beverages, increasing the size of the cold plate is not an option because of space limitations.
In an effort to solve the problems of bulk refrigeration, some systems, such as the system disclosed in U.S Pat. No. 4,856,678, attempt to precool the cold plate by collecting the melted ice water from the ice bin, and then passing the melted ice water through the cold plate. Although such systems may improve the performance of the beverage dispenser, they do not address the problems of increased volume demand and customer service associated with counter space and cold plate physical limitations. Indeed, some of these systems likely increase the cost to the retailer of operating and maintaining the systems because of the increased counter space required by the systems.
It is accordingly an object of the present invention to provide a more efficient bulk refrigeration system for a beverage dispenser, which is capable of dispensing a large volume of chilled beverages in multiple flavors and which is designed to minimize the operating and maintenance costs of the system to the retailer and minimize the counter space requirements.